1. Field of the Invention
The present invention generally relates to an arrangement of the LEDs, and more specifically to arranging the LEDs supplied by AC power with low loss and smooth illumination in a high expandable structure.
2. The Prior Arts
At present, the LED is a widely used semiconductor light source with one positive terminal and one negative terminal. The LED mainly comprises a PN junction as a light emitting layer which emits light when DC (direct current) voltage beyond the turn on threshold (i.e. forward voltage) is supplied. Thus, the LED needs DC power instead of conventional AC (alternative current) power. For the conventional AC power, such as city power or the output power from the electric motor, an appropriate rectifying device is usually used to transform the AC power to the DC power as desired. Thus, the entire cost increases and the complexity and the layout of the rectifying circuit is an issue for the reliability.
Therefore, it is needed to provide an arrangement of the LEDs to directly turn on by DC power without any rectifying device or other passive elements consuming some of the power so as to overcome the above mentioned drawbacks of the prior arts.